Unable to install or update application on Plesk server: The 'mysql' extension was not found

Applicable to:

Plesk for Linux

Symptoms

The installation or update of the application, e.g SugarCRM or Joomla, fails with the following error in Plesk UI:

PLESK_ERROR: Error: Unable to install the app because its installation requirements are not met. Contact your hosting provider to resolve this problem. Requirements PHP extension The 'mysql' extension was not found.

OR

PLESK_ERROR: The app requires PHP version later than 5.0 but earlier than 5.5. Your PHP is 7.0.31. If PHP is not available, ensure that the PHP support is selected for the domain.The 'mysql' extension was not found.